Driving game machine

ABSTRACT

A course coordinate system processor has a general automobile control unit, a movement decision unit, and a position decision unit. The general automobile control unit controls the running of a plurality of general automobiles on a straight road in a course coordinate system. The movement decision unit determines whether or not another automobile exists in front of an automobile which is under consideration for a movement decision. The position decision unit determines the positional relation between a player&#39;s automobile and general automobiles in the course coordinate system, and also determines general automobiles that are positioned in a predetermined visible range of the player&#39;s automobile. Positional coordinate data of the player&#39;s automobile have been transformed from a world coordinate system into the course coordinate system by a course coordinate system transformation unit.

This is a division of application Ser. No. 08/711,824, filed Sep. 10,1996 now U.S. Pat. No. 5,772,504.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a driving game machine which is playedby the player to simulate the driving of an automobile and whichdisplays on a display monitor a three-dimensional image that variesdepending on the manner in which the simulated automobile is driven bythe player.

2. Description of the Related Art

There have been in widespread use driving game machines that are playedby the player who is seated in a cockpit equipped with a steering wheel,an accelerator pedal, a brake pedal, etc., similar to the driver's seatof an actual automobile. while seeing a three-dimensional imagedisplayed on a display monitor, the player operates the steering wheel,the accelerator pedal, the brake pedal, etc. to drive a simulatedautomobile on the display monitor. The display monitor displays, on adisplayed road, the automobile driven by the player, a rival automobileor automobiles competing for a driving game, and general automobilesexisting as obstacles. The automobile driven by the player will bereferred to as the player's automobile, and the rival and generalautomobiles as other automobiles.

In a driving game played on the driving game machine, it is necessary todisplay when the player's automobile collides with another automobile,and the other automobiles are required to understand their positionalrelation to each other and move based on that understanding.Consequently, the positional relation between the player's automobileand the other automobiles and also between the other automobiles has tobe determined each time the image displayed on the display monitor isrefreshed. The positional relation between those displayed automobilescan relatively easily be determined if the displayed road along whichthe automobiles runs is flat and straight.

Usually, however, the displayed road is a three-dimensional road whichhas curves and ups and downs, because the player would lose interest inthe flat and straight road in the driving game. The positional relationbetween the displayed automobiles on such a three-dimensional road hasto be determined after the displayed positions of the player's and otherautomobiles are calculated in a three-dimensional coordinate system.Therefore, it will take a long period of time to determine thepositional relation between the displayed automobiles on thethree-dimensional road. It is laborious and time-consuming to produce aprogram which is capable of determining the positional relation on areal-time basis each time the displayed image is refreshed, resulting ina reduction in the efficiency of development of driving game machines.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a drivinggame machine which is capable of quickly and easily determining thepositional relation between the player's and other automobiles on areal-time basis.

According to the present invention, there is provided a driving gamemachine comprising three-dimensional data memory means for storingcoordinate data of a three-dimensional road established in a game spacein a three-dimensional coordinate system, two-dimensional data memorymeans for storing coordinate data of a straight road established in atwo-dimensional coordinate system in association with thethree-dimensional road, player's automobile control means forcontrolling a player's automobile on the three-dimensional road asinstructed by a player, general automobile control means for controllinggeneral automobiles on the straight road, two-dimensional coordinatetransforming means for transforming coordinate data of the player'sautomobile on the three-dimensional road into coordinate data on thestraight road in the two-dimensional coordinate system, and positiondeciding means for determining the positional relation between theplayer's automobile and the general automobiles based on the coordinatedata on the straight road in the two-dimensional coordinate system.

The position deciding means comprises means for determining generalautomobiles which are positioned in a predetermined visible range of theplayer's automobile, and the driving game machine further comprisesthree-dimensional coordinate transforming means for transformingcoordinate data of the general automobiles which are determined as beingpositioned in the predetermined visible range into coordinate data onthe three-dimensional road in the three-dimensional coordinate system;and image display processing means for displaying the player'sautomobile and the general automobiles whose coordinate data have beentransformed into the coordinate data on the three-dimensional road inthe three-dimensional coordinate system, on a display monitor accordingto three-dimensional image processing.

The driving game machine further comprises rival automobile controlmeans for controlling a rival automobile on the three-dimensional roadas instructed by a competing player. The two-dimensional coordinatetransforming means further comprises means for transforming coordinatedata of the rival automobile on the three-dimensional road intocoordinate data on the straight road in the two-dimensional coordinatesystem, and the position deciding means comprises means for determiningthe positional relation between the player's automobile and the rivalautomobile based on the coordinate data on the straight road in thetwo-dimensional coordinate system.

According to the present invention, there is also provided a drivinggame machine comprising player's automobile control means forcontrolling a player's automobile on a three-dimensional road in a gamespace in a three-dimensional coordinate system as instructed by aplayer, general automobile control means for controlling generalautomobiles on a straight road in a two-dimensional coordinate system,which is converted from the three-dimensional road, two-dimensionalcoordinate transforming means for transforming coordinate data of theplayer's automobile on the three-dimensional road into coordinate dataon the straight road in the two-dimensional coordinate system, positiondeciding means for determining the positional relation between theplayer's automobile and the general automobiles based on the coordinatedata on the straight road in the two-dimensional coordinate system, anddetermining general automobiles which are positioned in a predeterminedvisible range of the player's automobile, three-dimensional coordinatetransforming means for transforming coordinate data of the generalautomobiles which are determined as being positioned in thepredetermined visible range into coordinate data on thethree-dimensional road in the three-dimensional coordinate system, andimage display processing means for displaying the player's automobileand the general automobiles whose coordinate data have been transformedinto the coordinate data on the three-dimensional road in the imagespace in the three-dimensional coordinate system. The driving gamemachine further comprises rival automobile control means for controllinga rival automobile on the three-dimensional road as instructed acompeting player, wherein the two-dimensional coordinate transformingmeans further comprises means for transforming coordinate data of therival automobile on the three-dimensional road into coordinate data onthe straight road in the two-dimensional coordinate system, and theposition deciding means comprises means for determining the positionalrelation between the player's automobile and the rival automobile basedon the coordinate data on the straight road in the two-dimensionalcoordinate system.

The above and other objects, features, and advantages of the presentinvention will become apparent from the following description when takenin conjunction with the accompanying drawings which illustrate apreferred embodiment of the present invention by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a driving game machine according to thepresent invention;

FIG. 2 is a diagram showing a field of a driving game played on thedriving game machine;

FIG. 2A shows a three-dimensional word coordinate system;

FIG. 2B shows a three-coordinate local coordinate system;

FIG. 3 is a diagram showing a portion of a circuit road which is dividedinto road models;

FIG. 4 is a diagram showing a hypothetical straight road that isconverted from the circuit road along a center line thereof;

FIG. 5 is a block diagram of a control system of the driving gamemachine;

FIG. 6 is a flowchart of a sequence of making a movement decision;

FIG. 7 is a flowchart of an operation sequence of the driving gamemachine; and

FIG. 8 is a flowchart of a conversion subroutine in the operationsequence shown in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1, a driving game machine according to the presentinvention generally comprises a cockpit 1 and a display monitor 2. Thecockpit 1 has a driver's seat 3, a steering wheel 4, an acceleratorpedal 5, a brake pedal 6, and a gear change lever 7, similar to thedriver's seat of an actual automobile. The cockpit 1 also has a coininsertion slot 8 for inserting a coin therethrough, positioned in frontof the left-hand side of the driver's seat 3, and a start switch 9positioned on the right-hand side of the steering wheel 4. The displaymonitor 2 is located in front of the cockpit 1 at a position that caneasily be viewed by the player who is seated on the driver's seat 3. Thedisplay monitor 2 may comprise a CRT (cathode-ray tube), an LCD (liquidcrystal display), a projector, or the like for displaying imagesthereon.

Coordinate systems used in an image processing process for a drivinggame played on the driving game machine and a summary of such a drivinggame will be described below with reference to FIGS. 2 through 4.

FIG. 2 schematically shows a field 11 of a driving game played on thedriving game machine. The field 11 shown in FIG. 2 represents an entirespace that is expressed by a computer graphic image, and includes acircuit road 12 extending substantially along peripheral edges of thefield 11 and models (not shown) of buildings and other objects placedalong the circuit road 12. FIG. 3 fragmentarily shows the circuit road12. As shown in FIG. 3, the circuit road 12 has a start point and isdivided into road models 1, 2, 3, 4, 5, 6 spaced by respective distancesfrom the start point. Each of the road models 1, 2, 3, 4, 5, 6 is anindividual object that is displayed as a computer graphic image.

FIG. 2A also shows a three-dimensional world coordinate system (X, Y, Z)which is established in the field 11 in its entirety, and FIG. 2B showsa three-dimensional local coordinate system (x, y, z) which isestablished in a partial space in the field 11. Each of the road models1, 2, 3, 4, 5, 6 and the models of buildings and other objects isdescribed using its own inherent local coordinate system (x, y, z).

FIG. 4 illustrates a hypothetical straight road 120 that in convertedfrom the circuit road 12 along a center line thereof. A two-dimensionalcourse coordinate system (x, y) shown in FIG. 4 is established on thestraight road 120. The two-dimensional course coordinate system (x, y)has y coordinates which represent distances along the straight road 120from the start point, and x coordinates which represent transversepositions across the straight road 120. As shown in FIG. 4, the straightroad 120, i.e., the circuit road 12, has four lanes.

In a driving game played on the driving game machine by the playersitting in the cockpit 1, the player controls the steering wheel 4, theaccelerator pedal 5, the brake pedal 6, and the gear change lever 7,trying to drive the player's automobile displayed on the display monitor2 while passing general automobiles displayed on the display monitor 2,on the circuit road 12. The general automobiles running on the circuitroad 12 are controlled by the driving game machine. There are severaltens of general automobiles established by the driving game machine.Depending on the position and direction of the player's automobile, themodels of buildings and other objects along the circuit road 12 and thegeneral automobiles, which are positioned within a visible range, aredisplayed on the display monitor 2.

FIG. 5 shows in block form a control system of the driving game machineaccording to the present invention.

As shown in FIG. 5, the control system basically comprises the displaymonitor 2, the start switch 9, a coin detector 21, a driving controlassembly 22, a ROM (read-only memory) 23, a RAM (read-only memory) 24,and a controller 25.

When the start switch 9 is pressed by the player, the start switch 9issues a switch signal to the controller 25. when the coin detector 21detects a coin inserted through the coin insertion slot 8, it outputs acoin-detected signal to the controller 25.

The driving control assembly 22 comprises the steering wheel 4, theaccelerator pedal 5, the brake pedal 6, and the gear change lever 7. Thedriving control assembly 22 supplies various control data, representingan angular displacement of the steering wheel 4, depths to which theaccelerator pedal 5 and the brake pedal 6 are depressed, and a gearposition selected by the gear change lever 7, to the controller 25 wherethey are inputted to a player's automobile control unit 255 (describedlater on).

The ROM 23 stores a program of the driving game, coordinate data of thefield in the world coordinate system (X, Y, Z), coordinate data of themodels in the local coordinate system (x, y, z), course data in thecourse coordinate system (x, y), a program relative to automobilebehaviors according to the automobile engineering, data indicative ofthe correspondence between the world coordinate system (X, Y, Z) and thelocal coordinate system (x, y, z), and table data shown in Tables 1through 3, described below. The RAM 24 serves to temporarily storevarious data.

The controller 25 comprises a CPU (central processing unit), logiccircuits, and other circuit elements for controlling operation of thedriving game machine. The controller 25 determines whether a coin isinserted into the coin insertion slot 8 or not based on the signal fromthe coin detector 21, and also determines whether the start switch 9 ispressed by the player or not based on the signal from the start switch9.

The controller 25 has a world coordinate system processor 251, a coursecoordinate system processor 252, a course coordinate systemtransformation unit 253, and a world coordinate system transformationunit 254.

The world coordinate system processor 251, which carries out control inthe world coordinate system (X, Y, z), has a player's automobile controlunit 255 and an image display processor 256. The course coordinatesystem processor 252, which carries out control in the local coordinatesystem (x, y, z), has a general automobile control unit 257, a movementdecision unit 258, and a position decision unit 259.

The player's automobile control unit 255 controls the running of theplayer's automobile based on the various control data supplied from thedriving control assembly 22 according to the program, stored in the ROM23, relative to automobile behaviors according to the automobileengineering. The course coordinate system transformation unit 253transforms the coordinate data relative to the position of the player'sautomobile that is being controlled in the world coordinate system (X,Y, Z) into coordinate data in the course coordinate system (x, y).

The general automobile control unit 257 controls the running of thegeneral automobiles on the straight road 120 (see FIG. 4) in the coursecoordinate system (X, y) under preset conditions with respect to speeds,lane change frequencies, etc.

Since y coordinates in the course coordinate system (x, y) representdistances traveled by the general automobiles along the straight load120, the general automobile control unit 257 can easily determine thepositions of the general automobiles by adding the product of (samplinginterval)×(running speed) to the present y coordinates. In addition,since x coordinates in the course coordinate system (x, y) representtransverse positions of the general automobiles across the straight road120, the general automobile control unit 257 can easily determinedistances that the general automobiles have traveled transversely acrossthe straight road 120 such as for lane changes, by adding or subtractingthe product of (sampling interval)×(transversely moving speed) to orfrom the present x coordinates.

The position decision unit 259 determines the positional relationbetween the player's automobile and the general automobiles for acontact, a collision, etc., and the positional relation between thegeneral automobiles, and also determines general automobiles which arepositioned in a predetermined visible range of the player's automobile.The position decision unit 259 uses the coordinate data transformed bythe course coordinate system transformation unit 253 as the positionalcoordinate data of the player's automobile. The predetermined visiblerange of the player's automobile is defined by left and right angleswith respect to the direction in which the player's automobile travels,and a distance from the player's automobile.

When the position decision unit 259 determines a contact or collisionwith a general automobile, it delivers a collision signal to the imagedisplay processor 256.

The movement decision unit 258 determines whether the player'sautomobile or another general automobile exists in front of a generalautomobile which is under consideration for a movement decision,according to a process shown in FIG. 6, using the positional relationdetermined between the player's automobile and the general automobilesand also the positional relation between the general automobiles by theposition decision unit 259. The results determined by the movementdecision unit 258 are used by the general automobile control unit 257 tocontrol the running of the general automobiles. The movement decisionunit 258 may also determine whether there is an automobile existing inan adjacent lane or not for thereby determining whether the generalautomobile which is under consideration for a movement decision canchange lanes or not.

The world coordinate system transformation unit 254 transforms thepositional coordinate data of general automobiles that are determined tobe positioned in the visible range of the player's automobile by theposition decision unit 259, from the course coordinate system (x, y)into the world coordinate system (X, Y, Z).

The image display processor 256 displays the circuit road 12 (see FIG.2) in the visible range of the player's automobile, the models of thebuildings and other objects along the circuit road 12, and the generalautomobiles whose positional coordinate data have been transformed intothe world coordinate system (X, Y, Z), on the display monitor 2according to known three-dimensional image processing techniquesincluding geometry and rendering processes, depending on the positionand direction of the player's automobile which is controlled by theplayer's automobile control unit 255. when a collision signal issupplied from the position decision unit 259, the image displayprocessor 256 displays a spinning or vibrating image on the displaymonitor 2.

Inasmuch as the position decision unit 259 determines the positionalrelation between the player's automobile and the general automobiles andthe positional relation between the general automobiles, and alsodetermines general automobiles which are positioned in the visible rangeof the player's automobile in the two-dimensional course coordinatesystem (x, y), the position decision unit 259 can easily and quicklydetermine those positional relations.

The general automobiles are controlled by the course coordinate systemprocessor 252, and the positional coordinate data of only those generalautomobiles which are displayed on the display monitor 2 are transformedfrom the two-dimensional course coordinate system (x, y) into thethree-dimensional world coordinate system (X, Y. Z). Therefore, thenumber of general automobiles that can be controlled can be increasedwithout increasing the burden on the CPU of the controller 25. Theincreased number of general automobiles makes the driving game moreinteresting to the player, and also gives a more realistic look tothree-dimensional images displayed on the display monitor 2.

A process of making a movement decision with the movement decision unit258 will be described below with reference to FIG. 6.

It is assumed that an automobile which is under consideration for amovement decision has coordinates (x_(o), y₀) in the course coordinatesystem (x, y), an automobile k which is not under consideration for amovement decision have coordinates (x_(k), y_(k)) in the coursecoordinate system (x, y), each lane of the straight road 120 has a widthD, and k is an integer ranging from 1-n.

As shown in FIG. 6, the movement decision unit 258 determines whether ornot the difference x_(k) -x_(o) between the coordinates x_(k), x_(o). isequal to or smaller than the width D in a step S1. If the differencex_(k) -x_(o) is equal to or smaller than the width D (YES in the stepS1), then the movement decision unit 258 determines whether or not thecoordinate y_(k) is greater than the coordinate y_(o) in a stop S3. Ifthe coordinate y_(k) are greater than the coordinate y_(o) (YES in thestep S3), then th movement decision unit 258 decides that the automobilek is positioned in front of the automobile which is under considerationfor a movement decision in a step S5.

If the difference x_(k) -x_(o) is greater than the width D (NO in thestep S1), then the automobile k is not positioned in the same lane asthe automobile which is under consideration for a movement decision. Ifthe coordinate y_(k) is smaller than the coordinate y_(o) (NO in thestep S3), then the automobile k is not positioned in front of theautomobile which is under consideration for a movement decision. Ineither case, the movement decision unit 258 decides that the automobilek is not positioned in front of the automobile which is underconsideration for a movement decision in a step S7.

The above process is effected on other automobiles k (1∝n) than theautomobile which is under consideration for a movement decision, so thatall automobiles positions in front of the automobile which is underconsideration for a movement decision can be ascertained.

Heretofore, the above process of making a movement decision is the mostcomplex, and contains the largest number of processing steps, of allprocesses that make up the computerized control of the driving game. Fordriving the player's automobile on the display monitor 2 under the abovepreset conditions, it is necessary to determine whether anotherautomobile exists on the preset lane or not according to the aboveprocess of making a movement decision. If the positions of theautomobile were calculated using three-dimensional coordinate data andthe positional relationship between the automobiles were determined andthe above process of making a movement decision were carried out usingthe calculated positions for displaying a three-dimensional image, thenthe program of the driving game would be complex and contain a largenumber of processing steps.

However, according to the present invention, since the two-dimensionalcoordinate data in the course coordinate system are used by the movementdecision unit 258, the above process of making a movement decision canbe carried out easily as shown in FIG. 6. This allows many generalautomobiles, e.g., several tens of general automobiles, to be used inthe driving game, making the driving game more fun to play thanheretofore.

Operation of the driving game machine according to the present inventionwill be described below with reference to FIGS. 7 and 8.

As shown in FIG. 7, when the driving game machine is switched on, theimage display processor 256 displays a demonstration image on thedisplay monitor 2 in a step S11. Then, the controller 25 determineswhether a coin is inserted into the coin insertion slot 8 or not in astep S13. If not inserted (NO in the step S13), then the image displayprocessor 256 continuously displays the demonstration image on thedisplay monitor 2. If inserted (YES in the step S13), then the imagedisplay processor 256 displays a startup image on the display monitor 2in a step S15.

Then, the controller 25 determines whether the start switch 9 is pressedor not in a stop S17. If not pressed (NO in the step 17), then the imagedisplay processor 256 continuously displays the startup image on thedisplay monitor 2. If pressed (YES in the step S17), then the drivinggame is initiated, and the player operates the steering wheel 4, theaccelerator pedal 5, the brake pedal 6, and the gear change lever 7 ofthe driving control assembly 22 to drive the player's automobile.

Various control data outputted from the driving control assembly 22 aresupplied to the player's automobile control unit 255 in a step S19. Theplayer's automobile control unit 255 effects a simulation process ofsimulating the player's automobile based on the automobile engineeringaccording to the automobile behavior program stored in the ROM 23 in astep S21. Positional coordinate data of the player's automobile areproduced by the player's automobile control unit 255 in the simulationprocess, and supplied to the course coordinate system transformationunit 253, which transforms the positional coordinate data intopositional coordinate data in the course coordinate system (x, y) in astep S23.

Then, the positional data of the player's automobile in the positiondecision unit 259 are updated in a step S25. The general automobilecontrol unit 257 effects a process of moving the general automobilesdepending on the result determined by the movement decision unit 258 ina step S27.

Thereafter, the position decision unit 259 ascertains generalautomobiles that are positioned in the visible range of the player'sautomobile in a step S29. The world coordinate system transformationunit 254 transforms the positional coordinate data of the ascertainedgeneral automobiles from the course coordinate system (x, y) into theworld coordinate system (X, Y, Z) according to a subroutine describedlater on in a step S31.

Then, the image display processor 256 effects a three-dimensional imageprocess on the positional coordinate data of the general automobileswhich have been converted into the world coordinate system (X, Y, Z) andalso the data about the position and direction of the player'sautomobile which have been produced in the simulation process, anddisplays the player's automobile and the general automobiles on thedisplay monitor 2 in a step S33. Then, the controller 25 determineswhether a preset period of time has elapsed from the start of thedriving game or not in a step S35. If not elapsed (No in the step S35),then control returns to the step S19 to carry out the steps S19 throughS35 to repeat the above running control process. If elapsed (YES in thestep S35), then control comes to an end.

FIG. 8 shows the subroutine in the step S31 in greater detail.

First, as shown in FIG. 8, the position decision unit 259 refers to aroad model search table 1, partly shown below, to search for a roadmodel in which a general automobile is positioned, using the coordinatedata of the general automobile in the course coordinate system (x, y) ina step S41.

    ______________________________________                                        Road Model Search Table 1                                                     Distance (m)  Road model                                                      ______________________________________                                         0-100        1                                                               100-150         2                                                             150-200         3                                                             200-230         4                                                             230-400         5                                                             400-500         6                                                             .                           .                                                 .             .                                                               .             .                                                               ______________________________________                                    

The road model search table 1, which is partly shown above, is stored inthe ROM 23, and represents the association between the distance-relatedgroups of the y coordinates of the straight road 120 in the coursecoordinate system (x, y) and the road models of the straight road 120.

Thereafter, in a step S43, the position decision unit 259 refers to aroad model position data table 2, partly shown below, to search forcoordinate data in the world coordinate system (X, Y, Z) whichcorrespond to the origin of the local coordinate system (x, y, z) thatdescribes the road model obtained in the step S41.

    ______________________________________                                        Road Model Position Data Table 2                                              Road Model Position in world coordinate system                                ______________________________________                                        1          X.sub.1, Y.sub.1, Z.sub.1                                          2                X.sub.2, Y.sub.2, Z.sub.2                                    3                X.sub.3, Y.sub.3, Z.sub.3                                    4                X.sub.4, Y.sub.4, Z.sub.4                                    5                X.sub.5, Y.sub.5, Z.sub.5                                    6                X.sub.6, Y.sub.6, Z.sub.6                                    .                           .                                                 .          .                                                                  .          .                                                                  ______________________________________                                    

The road model position data table 2, which is partly shown above, isstored in the ROM 23, and represents the positional relation between thelocal coordinate system (x, y, z) which describes the configurationinformation of each if the road models and the world coordinate system(X, Y, Z).

Then, in a step S45, the position decision unit 259 refers to a roadmodel configuration table 3, partly shown below, to search forconfiguration information of the road model obtained in the step S41.

    ______________________________________                                        Road Model Configuration Table 3                                                     Road Configuration Information                                         Road                        Center of                                                                            Radius of                                  Model    Lanes  Shape       Curvature                                                                            Curvature                                  ______________________________________                                        1        4      Straight    --     --                                         2        4      Left Curve  (x.sub.2, y.sub.2, z.sub.2)                                                          r.sub.2                                    3        4      Straight    --     --                                         4        4      Right Curve (x.sub.4, y.sub.4, z.sub.4)                                                          r.sub.4                                    5        4      Straight    --     --                                         6        4      Left curve  (x.sub.6, y.sub.6, z.sub.6)                                                          r.sub.6                                    .        .                                                                    .        .                                                                    .        .                                                                    ______________________________________                                    

The road model shape table 3, which is partly shown above, is stored inthe ROM 23, and represents the information with respect to theconfiguration of each of the road models. The information with respectto the configuration of each of the road models includes the number oflanes, the shape, i.e., straight, left curve, or right curve, andadditionally the center and radius of curvature for left and rightcurves in the local coordinate system (x, y, z).

Then, in a step S47, the position decision unit 259 calculatescoordinate data of the automobile in the local coordinate system (x, y,z) of the road model from the coordinate data of the automobile in thecourse coordinate system (x, y) and the configuration informationobtained in the stop S45.

Finally, in a step S49, the position decision unit 259 calculatescoordinate data of the automobile in the world coordinate system (X, Y,Z) from the coordinate data of the road model in the world coordinatesystem (x, y, z), which have been obtained in the step S43, and thecoordinate data of the automobile in the local coordinate system (x, y,z).

In the subroutine shown in FIG. 8 for the coordinate transformation fromthe course coordinate system (x, y), automobiles that run in inner lanesalong a curve of the circuit board 12 may be somewhat decelerated, andautomobiles turn run in outer lanes along a curve of the circuit board12 may be somewhat accelerated thereby compensating for automobile speeddifferences between the straight road 120 and the circuit road 12.

In FIG. 3, the circuit road 12 may be divided into road models ofuniform length at constant distances or intervals. The road models ofuniform length can easily be searched for in the step S41 shown in FIG.8.

Two players can compete with each other in a driving game which isplayed using two driving game machines each identical to the drivinggame machine shown in FIG. 5.

The two driving game machines are connected to each other by acommunication cable. To allow the two driving game machines tocommunicate with each other, the controller 25 of each of the drivinggame machines additionally has a communication control unit 26 which isindicated by the dot-and-dash lines in FIG. 5.

The communication control unit 26 in the controller 25 of one of thedriving game machines transmits the coordinate data of the position ofthe player's automobile to the other driving game machine, and receivesthe player's automobile controlled by the other driving game machine,i.e., the coordinate data in the course coordinate system (x, y) of therival automobile controlled by the other driving game machine, and sendsthe received coordinate data to the position decision unit 259.

The position decision unit 259 determines the positional relationbetween the player's automobile and the rival automobile and also thepositional relation between the general automobiles and the rivalautomobile, and further determines whether the rival automobile which ispositioned in the preset visible range of the player's automobile. Whenthe position decision unit 259 determines a contact or collision betweenthe player's automobile and the rival automobile, it delivers acollision signal to the image display processor 256.

The movement decision unit 258 determines whether the rival automobileexists in front in the same lane as the player's automobile or not. Whenthe position decision unit 259 determines that the rival automobile ispositioned in the visible range of the player's automobile, the worldcoordinate system transformation unit 254 transforms the positionalcoordinate data of the rival automobile from the course coordinatesystem (x, y) into the world coordinate system (X, Y, Z). The imagedisplay processor 256 displays the rival automobile whose positionalcoordinate data have been transformed into the world coordinate system(X, Y, Z) on the display monitor 2.

As described above, the communication control units 26 in thecontrollers 25 of the two driving game machines exchange the positionaldata of the player's automobiles controlled by the respective drivinggame machines. Therefore, the players of the two driving game machinescan compete with each other in a driving game jointly played on thedriving game machines, and will find the driving game much moreinteresting.

Because the positional data of the rival automobile are handled as thetwo-dimensional coordinate data in the course coordinate system (x, y),the position decision unit 259 can easily and quickly determine thepositional relations and the whether rival automobile is in the visiblerange of the player's automobile. If three or more driving game machinesare interconnected through their respective communication control units26, then the number of rival automobiles involved in a driving gameplayed jointly on the driving game machines increases to the point wherethe players will be excited by the driving game as they compete withmany other rival automobiles simultaneously throughout during thedriving game.

The communication control unit 26 may transmit the positional coordinatedata of the player's automobile in the world coordinate system (X, Y, Z)which have been obtained by the player's automobile control unit 255,and also receive the positional coordinate data of the player'sautomobile in the world coordinate system (X, Y, Z) which is controlledby another driving game machine. In such a modification, the coursecoordinate system transformation unit 253 transforms the receivedpositional coordinate data into the course coordinate system (x, y), andthen delivers the transformed positional coordinate data to the positiondecision unit 259.

According to another modification, the interconnected driving gamemachines may be dispensed with their own individual controllers 25, butmay be controlled by a single controller 25 in a centralized controlsystem that governs all the driving game machines. In this modifiedarrangement, the single controller 25 does not need any communicationcontrol unit 26, but has course coordinate system processors 252associated respectively with the driving game machines. The singlecontroller 25 also has the course coordinate system processor 252, thecourse coordinate system transformation unit 253, and the worldcoordinate system transformation unit 254 for carrying out the samedecision and transformation processes as described above.

Although a certain preferred embodiment of the present invention hasbeen shown and described in detail, it should be understood that variouschanges and modifications may be made therein without departing from thescope of the appended claims.

What is claimed is:
 1. A driving game machine wherein a player automobile is displayed by a display device in a three-dimensional depiction along with at least one general automobile on a three-dimensional road, the driving game machine comprising:three-dimensional data memory means for storing coordinate data of said three-dimensional road in a three-dimensional coordinate system; two-dimensional data memory means for storing coordinate data of a two-dimensional road corresponding to said three-dimensional road transformed to a two-dimensional coordinate system; player automobile control means for controlling said player automobile on said three-dimensional road in response to input by a player and for generating three-dimensional player automobile coordinate data representing a position of said player automobile on said three-dimensional road; a dimensional coordinate system transforming means for transforming coordinate data between said two-dimensional coordinate system and said three-dimensional coordinate system; said two-dimensional coordinate system having a first coordinate axis corresponding to a road length of said three-dimensional road and a travel distance of said player automobile on said three-dimensional road being represented in terms of a first coordinate corresponding to a position on said first coordinate axis; an image display processor for driving said display device to produce said three-dimensional depiction based on said coordinate data of said three-dimensional road in said three-dimensional coordinate system; a course coordinate system processor for controlling said dimensional coordinate system transforming means and said image display processor to produce said three-dimensional depiction; and said course coordinate system processor including a general automobile control means for controlling said at least one general automobile on said two-dimensional road and for generating two-dimensional general automobile coordinate data representing a position of said general automobile on said two-dimensional road.
 2. The driving game machine as defined in claim 1, wherein said two-dimensional coordinate system has a second coordinate axis corresponding to a transverse direction of said three-dimensional road and a transverse displacement of said player automobile on said three-dimensional road being represented by a second coordinate along said second coordinate axis.
 3. The driving game machine as defined in claim 2, wherein said three-dimensional road is defined in sections corresponding to at least one of a straight model, a left curve model and a right curve model stored in said three-dimensional data memory means.
 4. The driving game machine as defined in claim 2, wherein said dimensional coordinate system transforming means transforms said coordinate data of said three-dimensional road in said three-dimensional coordinate system into coordinate data representing a straight road in said two-dimensional coordinate system such that a path along a centerline of said three-dimensional road is transformed into a straight line extending in a direction of said first coordinate axis in said two-dimensional coordinate system along a centerline of said two-dimensional road.
 5. The driving game machine as defined in claim 2, wherein said course coordinate system processor includes relative position determining means for determining a positional relationship between said player automobile and said at least one general automobile in said two-dimensional coordinate system.
 6. The driving game machine as defined in claim 2, further comprising:a first road memory means for storing road model search data correlating positions on said two-dimensional road along said first axis of said two-dimensional coordinate system with road model identifiers identifying road models; a second road memory means for storing road model position data correlating said road models with positions in said three-dimensional coordinate system of said three-dimensional road; a third road memory means for storing road model configuration data of said road models which define road configuration in a local three-dimensional coordinate system correlated to said three-dimensional coordinate system of said three-dimensional road by said road model position data; said course coordinate system processor controlling said dimensional coordinate system transforming means to produce three-dimensional coordinate system data in said three-dimensional coordinate system of said three-dimensional road, for producing said three-dimensional depiction showing said player automobile in a corresponding one of said road models, based on a position of said player automobile on said two-dimensional road by reading said road model search data to identify only said corresponding one of said road models correlated to said position of said player automobile on said two-dimensional road and only road model position data and road model configuration data for said corresponding one of said road models; and said course coordinate system processor controlling said image display processor using said three-dimensional coordinate system data in said three-dimensional coordinate system of said three-dimensional road to produce said three-dimensional depiction showing said player automobile in said corresponding one of said road models.
 7. The driving game machine as defined in claim 6 wherein said image display processor displays only said corresponding one of said road models at a given time.
 8. The driving game machine as defined in claim 2, further comprising:a first road memory means for storing road model search data correlating positions on said two-dimensional road along said first axis of said two-dimensional coordinate system with road model identifiers identifying road models; a second road memory means for storing road model position data correlating said road models with positions in said three-dimensional coordinate system of said three-dimensional road; a third road memory means for storing road model configuration data of said road models which define road configuration in a local three-dimensional coordinate system correlated to said three-dimensional coordinate system of said three-dimensional road by said road model position data; said dimensional coordinate system transforming means transforming said three-dimensional player automobile coordinate data generated by said player automobile control means into two dimensional player automobile coordinate data in said two-dimensional coordinate system of said two-dimensional road model; said course coordinate system processor identifying only a corresponding one of said road models based on said two-dimensional player automobile coordinate data by reading said road model search data corresponding to said two-dimensional player automobile coordinate data and reading corresponding ones of said road model position data and said road model configuration data; said course coordinate system processor controlling said dimensional coordinate system transforming means to calculate three-dimensional coordinate data of said player automobile in said local three-dimensional coordinate system of only said corresponding one of said road models at a given time based on said corresponding one of said road model configuration data and said two-dimensional player automobile coordinate data; said course coordinate system processor controlling said dimensional coordinate system transforming means to calculate three-dimensional coordinate data of said player automobile in said three-dimensional coordinate system of said three-dimensional road based on said three-dimensional coordinate data of said player automobile in said local three-dimensional coordinate system and only said corresponding one of said road model configuration data at said given time; and said course coordinate system processor controlling said display device to produce said three-dimensional depiction which shows said corresponding one of said road models with said player automobile depicted therein.
 9. The driving game machine as defined in claim 8, wherein said three-dimensional road is defined in sections corresponding to at least one of a straight model, a left curve model and a right curve model stored in said three-dimensional data memory means.
 10. The driving game machine as defined in claim 8, wherein: said road model memory means includes:a first road memory storing road model search data correlating positions on said two-dimensional road along said first axis of said two-dimensional coordinate system with road model identifiers identifying road models; a second road memory means for storing road model position data correlating said road models with positions in said three-dimensional coordinate system of said three-dimensional road; and a third road memory means for storing road model configuration data of said road models which define road configuration in a local three-dimensional coordinate system correlated to said three-dimensional coordinate system of said three-dimensional road by said road model position data; and said image display processing means transforms said road model configuration data of said select one of said road models from said local three-dimensional coordinate system into said three-dimensional coordinate system of said three-dimensional road using corresponding data of said road model position data.
 11. The driving game machine as defined in claim 1, wherein said dimensional coordinate system transforming means includes:a two-dimensional coordinate system transforming means for transforming coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road into coordinate data in said two-dimensional coordinate system corresponding to a position on said two-dimensional road; three-dimensional coordinate system transforming means for transforming coordinate data corresponding to a position on said two-dimensional road in said two-dimensional coordinate system into coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road; said two-dimensional coordinate system transforming means transforming said three-dimensional player automobile coordinate data of said player automobile on said three-dimensional road into two-dimensional player automobile coordinate data on said two-dimensional road in said two-dimensional coordinate system; and said three-dimensional coordinate system transforming means transforming said two-dimensional player automobile coordinate data of said player automobile on said two-dimensional road in said two-dimensional coordinate system into three-dimensional player automobile coordinate data in said three-dimensional coordinate system.
 12. The driving game machine as defined in claim 11, wherein:said course coordinate system processor includes:relative position determining means for determining a positional relationship between said player automobile and said at least one general automobile in said two-dimensional coordinate system; said relative position determining means including visible range determining means for determining whether said at least one general automobile is within a predetermined visible range of said player automobile; control means for controlling said three-dimensional coordinate system transforming means to transform said two-dimensional general automobile coordinate data of said at least one general automobile in said two-dimensional coordinate system into three-dimensional general automobile coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road only if said visible range determining means determines that said at least one general automobile is within a predetermined visible range of said player automobile; and control means to control said image display processor to display on said display device said at least one general automobile having coordinate data transformed into said three-dimensional general automobile coordinate data in said three-dimensional coordinate system.
 13. The driving game machine as defined in claim 11, further comprising:said at least one general automobile including a plurality of general automobiles; said course coordinate system processor including relative position determining means for determining positional relationships between said player automobile and said plurality of general automobiles in said two-dimensional coordinate system; said relative position determining means including visible range determining means for identifying individual ones of said plurality of general automobiles that are within a predetermined visible range of said player automobile; and said course coordinate system processor controlling said three-dimensional coordinate system transforming means to transform coordinate data of said individual ones of said plurality of general automobiles in said two-dimensional coordinate system into coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road and not transforming coordinate data of other ones of said plurality of general automobiles not included in said individual ones of said plurality of general automobiles; and an image display processor for displaying on said display device said individual ones of said plurality of general automobiles having said coordinate data transformed into said three-dimensional coordinate system using said coordinate data transformed into said three-dimensional coordinate system.
 14. A driving game machine wherein a player automobile is displayed by a display device in a three-dimensional depiction along with general automobiles on a three-dimensional road, the driving game machine comprising:three-dimensional data memory means for storing coordinate data of said three-dimensional road in a three-dimensional coordinate system; two-dimensional data memory means for storing coordinate data of a two-dimensional road corresponding to said three-dimensional road transformed to a two-dimensional coordinate system; player automobile control means for controlling said player automobile on said three-dimensional road in response to input by a player and for generating three-dimensional player automobile coordinate data representing a position of said player automobile on said three-dimensional road; general automobile control means for controlling said general automobiles on said two-dimensional road and for generating two-dimensional general automobile coordinate data representing positions of said general automobiles on said two-dimensional road; a dimensional coordinate system transforming means for transforming coordinate data between said two-dimensional coordinate system and said three-dimensional coordinate system; said two-dimensional coordinate system having a first coordinate axis corresponding to a road length of said three-dimensional road and a travel distance of said player automobile on said three-dimensional road being represented in terms of a first coordinate corresponding to a position on said first coordinate axis; said dimensional coordinate system transforming means including:a two-dimensional coordinate system transforming means for transforming coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road into coordinate data in said two-dimensional coordinate system corresponding to a position on said two-dimensional road; three-dimensional coordinate system transforming means for transforming coordinate data corresponding to a position on said two-dimensional road in said two-dimensional coordinate system into coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road; said two-dimensional coordinate system transforming means transforming said three-dimensional player automobile coordinate data of said player automobile on said three-dimensional road into two-dimensional player automobile coordinate data on said two-dimensional road in said two-dimensional coordinate system; and said three-dimensional coordinate system transforming means transforming said two-dimensional player automobile coordinate data of said player automobile on said two-dimensional road in said two-dimensional coordinate system into three-dimensional player automobile coordinate data on said three-dimensional road; relative position determining means for determining positional relationships between said player automobile and said plurality of general automobiles in said two-dimensional coordinate system; said relative position determining means including visible range determining means for identifying individual ones of said plurality of general automobiles that are within a predetermined visible range of said player automobile; said three-dimensional coordinate system transforming means transforming coordinate said two-dimensional general automobile data of said individual ones of said plurality of general automobiles in said two-dimensional coordinate system into three-dimensional general automobile coordinate data in said three-dimensional coordinate system corresponding to a position on said three-dimensional road and not transforming coordinate data of other ones of said plurality of general automobiles not included in said individual ones of said plurality of general automobiles; a road model memory means for storing road models in said three-dimensional coordinate system correlated to positions along said first axis of said two-dimensional coordinate system representing positions on said two-dimensional road; road model selection means for selecting one of said road models corresponding to positions on said first axis, of said two-dimensional coordinate system, of said individual ones of said plurality of general automobiles that are within said predetermined visible range of said player automobile; and image display processing means for displaying on said display device said individual ones of said plurality of general automobiles having coordinate data transformed into said three-dimensional coordinate system in said selected one of said road models. 